Tubing and casing stripper for wells



A 30, 1938. c, R, PHILUPS 2,128,593

TUlING AND CASING STRIPPER FOR WELLS Filed April 14, 1958 E i E E 5 Alia ff:

IN [EN-FOE ATTORNEY Patented Aug. 30, 1938 UNITED STATES PATENT OFFlCE TUBING AND CASING STRIPPER FOR WELLS Charles R. Phillips, Mannington, W. Va.

Application April 14, 1938, Serial No. 201,969

4 Claims.

This invention relates broadly to a tool for facilitating the withdrawal and removal of tubing or casing from wells, and more particularly to a tool adapted to be used in the freeing of certain sections of well tubing or casing that offer obstinate resistance to withdrawal.

One of the objects of the invention is to provide a cutting tool or casing ripper adapted to be lowered into the tubing or casing of a well and then operated to cut or slit the lower end of a section of tubing or casing so that said section may be pulled or stripped from a coupling or collar by means of which two adjacent sections are connected.

Another object of the invention is to provide a tool of the character referred to wherein the cutter blade may, after performing its desired func tion, be automatically retracted toinoperative position out of contact with the tubing or casing, thus facilitating removal of the tool from the well. Such automatic retraction of the cutter blade after cutting prevents objectionable mutilation of the coupling; prevents the blade from perforating the casing after slitting the tube, and prevents the blade from being broken by engagement with the wall of the well.

With these and other objects in view, the invention resides in the features of construction, arrangement of parts, and combination of elements which will hereinafter be described, reference being had to the accompanying drawing, in which Figure 1 is a side elevational view of the device in a well tubing or casing;

Figure 2 is a detail view, in side elevation, of the cutting mechanism, parts thereof being broken away;

Figure 3 is a front or face view of the same;

Figure 4 is a sectional view taken on line 4-4 of Fig. 2; and

Figure 5 is a detail view of an end of a section of tubing or casing after slitting.

The device comprises a rod 1 having leaf springs 2 attached thereto for properly guiding and positioning the tool in the tubing or casing 3.

The housing 4 for the cutting mechanism is located at the upper end of the rod I. Snugly received within a pocket 5 provided in the housing t and maintained therein by .a pin 6 are spaced plates 1, the latter being fastened together to form a unit by rivets 8. Each plate I has a slot 9 provided in its wall .and slidably received within each slot 9 is a slide block it. A pin ll connects the two slide blocks and pivotally supported on said pin H intermediate the plates 1 is the cutting blade l2, the cutting point or edge normally protruding outwardly of the tool and in contact with the tubing or casing by reason of the provision of a spring pressed pin I3 which underlies the blade l2 adjacent its inner end and exerts an upward pressure thereon.

Said spring and pin l3 are housed in an aperture provided in a spacing member I5 interposed between the two plates 1 below the cutter l2, and. the upper end of said spacer terminates in a shoulder I6 whose forward edge abuts the inner extremity of the cutter [2. As shown in Fig. 2, the inner extremity of the cutter i2 is curved on a radius corresponding to the curvature of the forward end of the shoulder so that the two elements snugly interfit. When in this position, the slide blocks H) occupy a forward position in the slots 9 and the cutting edge of the blade l2 protrudes from the tool in operative position.

When it is desired to strip a section of the tubing from a well,- the device is lowered into the tubing 3 by a cable (not shown) until it reaches the desired point, which point is always at a location in the depth of the well where two sections 3 are joined together by .a collar I'I. During lowering of the tool into the well, the cutter blade I! frictionally rides inoperatively against the tubing 3 and against the pressure exerted by the spring presed pin l3. When, however, the point to be severed is reached, the spring impelled cutter I2 is forced outwardly beneath the lower end of the section of tubing 3 and the leaf springs 2 frictionally contact the inner surface of the well tubing and function to maintain the tool in operative position, as illustrated in Fig. 1.

With the tool so positioned it is drawn upwardly by its supporting cable. Such elevation results in the cutting edge of the blade l2 gouging into the tubing 3 and continued elevation of the tool cuts a slit (shown at 20 in Fig. 5) in said tubing, thus ripping the tubing from its collar 11. When the upper end of the collar is reached in the ripping operation, the point of the cutting edge of the blade l2 will be projected outwardly through the tubing and engaged thereby, and continued elevation of the tool will result in slight rotation of the cutter l2 on its pin ll. As the cutter rotates, its rear or inner extremity is brought out of abutting relation with the fixed shoulder I6. Being thus left unsupported, the slide blocks I!) move rearwardly in their slots 9 because of the pressure of the tubing on the cutting edge of the blade l2, and, as a consequence, the entire mechanism, including the cutter I2, is retracted inwardly and the cutting edge of the blade I2 is brought out of contact with the tubing and gravitates about its pivot pin II to a recess 22 between the two plates 1. As a result, the cutter is entirely confined within the tool after the cutting operation is completed so that neither the tubing, the collar, or the tool can thereafter be damaged by withdrawal of the tool from the well.

After ripping and withdrawal of the tool, the ripped section may be removed from the well, after which an appropriate fishing toolmay be engaged with the collar and the balance removed.

Although I have illustrated and described certain of the preferred embodiments of the invention, it will be apparent that various changes and alterations might be made in the general form and arrangement of parts described without departing from the invention. Hence, it is not intended to be limited to the precise details set forth, and I shall consider myself at liberty. to make such changes and alterations as fairly "fall within the spirit and scope of the appended claims.

What is claimed is:-

1. A tool for cutting well casing sections comprising a housing, a cutter blade pivoted in said housing and having a cutting edge at its outer end projecting from the housing, means whereby the cutter blade may be moved inwardly of said housing to retracted position in said housing, and means in said housing and engageable with the cutter blade for maintaining it in its outward operative position, said last mentioned means being adapted to be disengaged from said blade following movement of the blade about its pivot in a prescribed arc to permit said cutter blade to be retracted within the housing.

2. A tool for cutting well casing sections comprising a housing, a cutter blade having its cutting edge projecting from said housing, pivotal means for supporting said cutter blade, said pivotal means being slidable inwardly and outwardly of said housing, fixed means in said housing and engageable with the cutter blade for maintaining the cutting edge outwardly of said housing, said last mentioned means being adapted to be disengaged from said blade following movement of the blade in a prescribed arc about its pivot to permit the pivotal means to move inwardly of said housing for retracting the cutter blade.

3. A tool for cutting well casing sections comprising a housing, a cutter blade pivoted in said housing and having a cutting edge at its outer end projecting from the housing, means permitting the cutter blade to be moved inwardly of said housing to retracted position in said housing, a fixed shoulder in said housing engageable with the inner end of said cutter blade for maintaining the latter in its outward operative position, said blade being adapted to be brought out of abutting relation with said shoulder following movement 'ofthe blade about its pivot in a prescribed arc whereby said blade is permitted to be retracted to inoperative position inwardly of the housing.

4. A tool for cutting well casing sectionscomprising a housing, oppositely disposed transverse slots provided in said housing adapted to receive slide blocks therein, a pivot pin connecting said slide blocks and supporting a cutter blade, means in said housing and engageable with the.cutter blade for maintaining said slide blocks in a forwardly position in their slots so that the cutting edge of the blade protrudes outwardly of the housing, said last mentioned means being adapted to be disengaged from said blade following movement of the blade about its pivot in a prescribed arc so that said slide blocks are permitted to move rearwardly in their slots to retract the cutter blade to inoperative position.

CHARLES R. PHILLIPS. 

